The present invention relates generally to an apparatus and a method for simulating turbine and compressor performance and, in particular, to such use in engine modeling and control.
One-dimensional Computational fluid dynamics (CFD) codes are used to calculate fluid flow in many types of internal combustion engines. These codes use a gas dynamic model for predicting the gas flows in an engine. The approach is described in John B. Heywood, “Internal Combustion Engine Fundamentals”, pp. 756-762. In these CFD codes, compressor and turbine performance maps are typically used to impose a steady state mass flow rate.
Various examples of modeling and uses of look up tables for control are provided in the following documents:
The U.S. Pat. No. 5,526,266 discloses a method for diagnosing an engine using a computer based boost pressure model that compares actual measured boost pressure values from a turbocharger with modeled boost pressure values.
The U.S. Pat. No. 5,753,805 discloses a method for determining pneumatic states in an internal combustion engine system that utilizes look up tables in determining pressure and temperature density corrections for mass flow calculations.
The U.S. Pat. No. 5,915,917 discloses a compressor stall and surge control using airflow asymmetry measurement. Asymmetry function is measured by static pressure sensors or total pressure sensors located along the circumference of the compressor inlet, which provides pressure signals to a signal processor.
The U.S. Pat. No. 6,098,010 discloses a method and apparatus for predicting and stabilizing compressor stall that utilizes axial velocity measurements as a function of time to predict stall.
The U.S. Pat. No. 6,178,749 discloses a method of reducing turbo lag in diesel engines having exhaust gas recirculation that generates a turbocharger control signal based on actual and modeled intake manifold absolute pressure and mass airflow values.
The U.S. Pat. No. 6,298,718 discloses a turbocharger compressor diagnostic system wherein sensor data is verified with a “rationality test” and then compared to a compressor operation map to determine if the compressor is in surge or choke.
The U.S. Pat. No. 6,510,691 discloses a method for regulating or controlling a supercharged internal combustion engine having a turbocharger with variable turbine geometry that utilizes upper and lower ranges based on different operating states to determine the required adjustments for the variable geometry of the turbocharger.
The published U.S. Patent Application No. 2003/0101723 discloses a method for controlling a charge pressure in an internal combustion engine with an exhaust gas turbocharger that calculates a manipulated variable by comparing the power or torque or a compressor with a power or torque loss occurring in transmission from a turbine to the compressor and then utilizes the manipulated variable to set the charge pressure output of the compressor.
The published U.S. Patent Application No. 2003/0106541 discloses a control system for an internal combustion engine boosted with an electronically controlled compressor that utilizes lookup tables or factors that are combined to generate low and high idle speed factors for the compressor.
The published U.S. Patent Application No. 2003/0216856 discloses diagnostic systems for turbocharged engines that utilize inputs from a plurality of sensors provided to an engine control module to determine performance of the turbocharger based on predicted versus actual value in comparison to stored compressor and turbine maps.
The published U.S. Patent Application No. 2005/0131620 discloses a control system that utilizes a predictive model, a control algorithm, and a steady state map having look-up tables for controlling boost and exhaust gas recirculation (EGR) valve operation of a diesel engine.
The U.S. Pat. No. 3,738,102 discloses a fuel control for turbine type power plant having variable area geometry that controls the turbine by determining a “APIP” value and the U.S. Pat. No. 5,381,775 discloses a system for controlling an internal combustion engine that includes a controller receiving a signal from a summation point that is in communication with a characteristics map and a simulation.